/*!
    \file  dfu_core.c
    \brief USB DFU device class core functions

    \version 2014-12-26, V1.0.0, firmware for GD32F10x
    \version 2017-06-20, V2.0.0, firmware for GD32F10x
    \version 2018-07-31, V2.1.0, firmware for GD32F10x
*/

/*
    Copyright (c) 2018, GigaDevice Semiconductor Inc.

    All rights reserved.

    Redistribution and use in source and binary forms, with or without modification, 
are permitted provided that the following conditions are met:

    1. Redistributions of source code must retain the above copyright notice, this 
       list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright notice, 
       this list of conditions and the following disclaimer in the documentation 
       and/or other materials provided with the distribution.
    3. Neither the name of the copyright holder nor the names of its contributors 
       may be used to endorse or promote products derived from this software without 
       specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
OF SUCH DAMAGE.
*/

#include "dfu_core.h"
#include "systick.h"
#include "usbd_int.h"

#define USBD_VID                     0x28e9
#define USBD_PID                     0x0189

/* DFU requests management functions */
static void dfu_detach     (void *pudev, usb_device_req_struct *req);
static void dfu_dnload     (void *pudev, usb_device_req_struct *req);
static void dfu_upload     (void *pudev, usb_device_req_struct *req);
static void dfu_getstatus  (void *pudev, usb_device_req_struct *req);
static void dfu_clrstatus  (void *pudev, usb_device_req_struct *req);
static void dfu_getstate   (void *pudev, usb_device_req_struct *req);
static void dfu_abort      (void *pudev, usb_device_req_struct *req);

static void dfu_mode_leave (void *pudev);

static uint8_t dfu_getstatus_complete (void *pudev);

static void (*dfu_request_process[])(void *pudev, usb_device_req_struct *req) = 
{
    dfu_detach,
    dfu_dnload,
    dfu_upload,
    dfu_getstatus,
    dfu_clrstatus,
    dfu_getstate,
    dfu_abort
};

/* data management variables */
static __IO uint32_t g_usbd_dfu_altset = 0;

usbd_int_cb_struct *usbd_int_fops = NULL;

/* note:it should use the c99 standard when compiling the below codes */
/* USB standard device descriptor */
const usb_descriptor_device_struct device_descripter =
{
    .Header = 
     {
         .bLength = USB_DEVICE_DESC_SIZE, 
         .bDescriptorType = USB_DESCTYPE_DEVICE
     },
    .bcdUSB = 0x0200,
    .bDeviceClass = 0x00,
    .bDeviceSubClass = 0x00,
    .bDeviceProtocol = 0x00,
    .bMaxPacketSize0 = USBD_EP0_MAX_SIZE,
    .idVendor = USBD_VID,
    .idProduct = USBD_PID,
    .bcdDevice = 0x0100,
    .iManufacturer = USBD_MFC_STR_IDX,
    .iProduct = USBD_PRODUCT_STR_IDX,
    .iSerialNumber = USBD_SERIAL_STR_IDX,
    .bNumberConfigurations = USBD_CFG_MAX_NUM
};

/* USB device configuration descriptor */
const usb_descriptor_configuration_set_struct configuration_descriptor = 
{
    .Config = 
    {
        .Header = 
         {
             .bLength = sizeof(usb_descriptor_configuration_struct), 
             .bDescriptorType = USB_DESCTYPE_CONFIGURATION 
         },
        .wTotalLength = USB_DFU_CONFIG_DESC_SIZE,
        .bNumInterfaces = 0x01,
        .bConfigurationValue = 0x01,
        .iConfiguration = 0x00,
        .bmAttributes = 0x80,
        .bMaxPower = 0x32
    },

    .DFU_Interface = 
    {
        .Header = 
         {
             .bLength = sizeof(usb_descriptor_interface_struct), 
             .bDescriptorType = USB_DESCTYPE_INTERFACE 
         },
        .bInterfaceNumber = 0x00,
        .bAlternateSetting = 0x00,
        .bNumEndpoints = 0x00,
        .bInterfaceClass = 0xFE,
        .bInterfaceSubClass = 0x01,
        .bInterfaceProtocol = 0x02,
        .iInterface = 0x00
    },

    .DFU_Function_Desc = 
    {
        .Header = 
         {
            .bLength = sizeof(usb_dfu_function_descriptor_struct), 
            .bDescriptorType = DFU_DESC_TYPE 
         },
        .bmAttributes = 0x0B,
        .wDetachTimeOut = 0x00FF,
        .wTransferSize = TRANSFER_SIZE,
        .bcdDFUVersion = 0x011A,
    },
};

/* USB language ID Descriptor */
const usb_descriptor_language_id_struct usbd_language_id_desc = 
{
    .Header = 
     {
         .bLength = sizeof(usb_descriptor_language_id_struct), 
         .bDescriptorType = USB_DESCTYPE_STRING
     },
    .wLANGID = ENG_LANGID
};

/* USB serial string */
uint8_t usbd_serial_string[USB_SERIAL_STRING_SIZE] =
{
    USB_SERIAL_STRING_SIZE,
    USB_DESCTYPE_STRING,
};

void *const usbd_strings[] = 
{
    [USBD_LANGID_STR_IDX] = (uint8_t *)&usbd_language_id_desc,
    [USBD_MFC_STR_IDX] = USBD_STRING_DESC("GigaDevice"),
    [USBD_PRODUCT_STR_IDX] = USBD_STRING_DESC("GD32 USB DFU in FS Mode"),
    [USBD_SERIAL_STR_IDX] = usbd_serial_string,
	  [USBD_CONFIG_STR_IDX] = USBD_STRING_DESC("GD32 USB CONFIG"),
    [USBD_INTERFACE_STR_IDX] = USBD_STRING_DESC(FLASH_IF_STRING)
};

dfu_status_struct dfu_status;

uint8_t manifest_state = MANIFEST_COMPLETE;

struct 
{
    uint8_t buf[TRANSFER_SIZE];
    uint16_t data_len;
    uint16_t block_num;
    uint32_t base_addr;
} prog_struct = {{0}, 0, 0, APP_LOADED_ADDR};

/*!
    \brief      initialize the MSC device
    \param[in]  pudev: pointer to usb device instance
    \param[in]  config_index: configuration index
    \param[out] none
    \retval     usb device operation status
*/
usbd_status_enum dfu_init (void *pudev, uint8_t config_index)
{
    /* unlock the internal flash */
    fmc_unlock();

    systick_config();

    return USBD_OK;
}

/*!
    \brief      de-initialize the MSC device
    \param[in]  pudev: pointer to usb device instance
    \param[in]  config_index: configuration index
    \param[out] none
    \retval     usb device operation status
*/
usbd_status_enum  dfu_deinit (void *pudev, uint8_t config_index)
{
    /* restore device default state */
    dfu_status.bStatus = STATUS_OK;
    dfu_status.bState = STATE_dfuIDLE;

    prog_struct.block_num = 0;
    prog_struct.data_len = 0;

    /* lock the internal flash */
    fmc_lock();

    return USBD_OK;
}

/*!
    \brief      handle the MSC class-specific requests
    \param[in]  pudev: pointer to usb device instance
    \param[in]  req: device class-specific request
    \param[out] none
    \retval     usb device operation status
*/
usbd_status_enum dfu_req_handler (void *pudev, usb_device_req_struct *req)
{
    switch (req->bmRequestType & USB_REQ_MASK) {
    case USB_CLASS_REQ:
        if (req->bRequest < DFU_REQ_MAX) {
            dfu_request_process[req->bRequest](pudev, req);
        } else {
            usbd_enum_error(pudev, req);
            return USBD_FAIL;
        }
        break;
    case USB_STANDARD_REQ:
        /* standard device request */
        switch (req->bRequest) {
        case USBREQ_GET_INTERFACE:
            usbd_ep_tx (pudev, EP0_IN, (uint8_t *)&g_usbd_dfu_altset, 1);
            break;
        case USBREQ_SET_INTERFACE:
            g_usbd_dfu_altset = (uint8_t)(req->wValue);
            break;
        default:
            break;
        }
        break;
    default:
        break;
    }

    return USBD_OK;
}

/*!
    \brief      handle data Stage
    \param[in]  pudev: pointer to usb device instance
    \param[in]  rx_tx: the flag of Rx or Tx
    \param[in]  ep_id: the endpoint ID
    \param[out] none
    \retval     usb device operation status
*/
usbd_status_enum  dfu_data_handler (void *pudev, usbd_dir_enum rx_tx, uint8_t ep_id)
{
    if ((USBD_TX == rx_tx) && ((DFU_IN_EP & 0x7F) == ep_id)) {
        dfu_getstatus_complete(pudev);

        return USBD_OK;
    }

    return USBD_FAIL;
}

/*!
    \brief      handle data IN stage in control endpoint 0
    \param[in]  pudev: pointer to usb device instance
    \param[out] none
    \retval     usb device operation status
  */
static uint8_t  dfu_getstatus_complete (void *pudev)
{
    uint32_t addr;

    if (STATE_dfuDNBUSY == dfu_status.bState) {
        /* decode the special command */
        if (0 == prog_struct.block_num) {
            if (1 == prog_struct.data_len){
                if (GET_COMMANDS == prog_struct.buf[0]) {
                    /* no operation */
                } else {
                    goto command_error;
                }
            } else if (5 == prog_struct.data_len) {
                if(SET_ADDRESS_POINTER == prog_struct.buf[0]) {
                    /* set flash operation address */
                    prog_struct.base_addr = *(uint32_t *)(prog_struct.buf + 1);
                } else if(ERASE == prog_struct.buf[0]) {
                    prog_struct.base_addr = *(uint32_t *)(prog_struct.buf + 1);

                    fmc_page_erase(prog_struct.base_addr);
                } else {
                    goto command_error;
                }
            } else {
command_error:  usbd_enum_error(pudev, NULL);
            }
        } else if (prog_struct.block_num > 1) {  /* regular download command */
            /* preform the write operation */
            uint32_t idx = 0;

            /* decode the required address */
            addr = (prog_struct.block_num - 2) * TRANSFER_SIZE + prog_struct.base_addr;

            if (prog_struct.data_len & 0x03) { /* not an aligned data */
                for (idx = prog_struct.data_len; idx < ((prog_struct.data_len & 0xFFFC) + 4); idx++) {
                    prog_struct.buf[idx] = 0xFF;
                }
            }

            /* data received are word multiple */
            for (idx = 0; idx < prog_struct.data_len; idx += 4) {
                fmc_word_program(addr, *(uint32_t *)(prog_struct.buf + idx));
                addr += 4;
            }
            prog_struct.block_num = 0;
        }

        prog_struct.data_len = 0;

        /* update the device state and poll timeout */
        dfu_status.bState = STATE_dfuDNLOAD_SYNC;

        return USBD_OK;
    } else if (dfu_status.bState == STATE_dfuMANIFEST) {  /* manifestation in progress */
        /* start leaving DFU mode */
        dfu_mode_leave(pudev);
    }

    return USBD_OK;
}

/*!
    \brief      handle the DFU_DETACH request
    \param[in]  pudev: pointer to usb device instance
    \param[in]  req: DFU class request
    \param[out] none
    \retval     none.
*/
static void dfu_detach(void *pudev, usb_device_req_struct *req)
{
    switch (dfu_status.bState) {
    case STATE_dfuIDLE:
    case STATE_dfuDNLOAD_SYNC:
    case STATE_dfuDNLOAD_IDLE:
    case STATE_dfuMANIFEST_SYNC:
    case STATE_dfuUPLOAD_IDLE:
        dfu_status.bStatus = STATUS_OK;
        dfu_status.bState = STATE_dfuIDLE;
        dfu_status.iString = 0; /* iString */
        prog_struct.block_num = 0;
        prog_struct.data_len = 0;
        break;
    default:
        break;
    }

    /* check the detach capability in the DFU functional descriptor */
    if (configuration_descriptor.DFU_Function_Desc.wDetachTimeOut & DFU_DETACH_MASK) {
        /* perform an unconnected operation on USB bus */
        gpio_bit_reset(USB_PULLUP, USB_PULLUP_PIN);
        ((usbd_core_handle_struct *)pudev)->status = USBD_UNCONNECTED;

        /* perform an connected operation on USB bus */
        gpio_bit_set(USB_PULLUP, USB_PULLUP_PIN);
        ((usbd_core_handle_struct *)pudev)->status = USBD_CONNECTED;
    } else {
        /* wait for the period of time specified in detach request */
        delay_1ms (4);
    }
}

/*!
    \brief      handle the DFU_DNLOAD request
    \param[in]  pudev: pointer to usb device instance
    \param[in]  req: DFU class request
    \param[out] none
    \retval     none
*/
static void dfu_dnload(void *pudev, usb_device_req_struct *req)
{
    switch (dfu_status.bState) {
    case STATE_dfuIDLE:
    case STATE_dfuDNLOAD_IDLE:
        if (req->wLength > 0) {
            /* update the global length and block number */
            prog_struct.block_num = req->wValue;
            prog_struct.data_len = req->wLength;
            dfu_status.bState = STATE_dfuDNLOAD_SYNC;

            /* enable EP0 prepare receive the buffer */
            usbd_ep_rx (pudev, EP0_OUT, (uint8_t*)prog_struct.buf, prog_struct.data_len);
        } else {
            manifest_state = MANIFEST_IN_PROGRESS;
            dfu_status.bState = STATE_dfuMANIFEST_SYNC;
        }
        break;
    default:
        usbd_enum_error(pudev, req);
        break;
    }
}

/*!
    \brief      handles the DFU UPLOAD request.
    \param[in]  pudev: pointer to usb device instance
    \param[in]  req: DFU class request
    \param[out] none
    \retval     none
*/
static void  dfu_upload (void *pudev, usb_device_req_struct *req)
{
    uint8_t *phy_addr = NULL;
    uint32_t addr = 0;

    if(req->wLength <= 0) {
        dfu_status.bState = STATE_dfuIDLE;
        return;
    }

    switch (dfu_status.bState) {
    case STATE_dfuIDLE:
    case STATE_dfuUPLOAD_IDLE:
        /* update the global length and block number */
        prog_struct.block_num = req->wValue;
        prog_struct.data_len = req->wLength;

        /* DFU Get Command */
        if (prog_struct.block_num == 0) {
            /* update the state machine */
            dfu_status.bState = (prog_struct.data_len > 3) ? STATE_dfuIDLE : STATE_dfuUPLOAD_IDLE;

            /* store the values of all supported commands */
            prog_struct.buf[0] = GET_COMMANDS;
            prog_struct.buf[1] = SET_ADDRESS_POINTER;
            prog_struct.buf[2] = ERASE;

            /* send the status data over EP0 */
            usbd_ep_tx (pudev, EP0_IN, (uint8_t *)(&(prog_struct.buf[0])), 3);
        } else if (prog_struct.block_num > 1) {
            dfu_status.bState = STATE_dfuUPLOAD_IDLE;

            /* change is accelerated */
            addr = (prog_struct.block_num - 2) * TRANSFER_SIZE + prog_struct.base_addr;

            /* return the physical address where data are stored */
            phy_addr = (uint8_t *)(addr);

            /* send the status data over EP0 */
            usbd_ep_tx (pudev, EP0_IN, phy_addr, prog_struct.data_len);
        } else {
            dfu_status.bState = STATUS_errSTALLEDPKT;

            usbd_enum_error (pudev, req);
        }
        break;
    default:
        prog_struct.data_len = 0;
        prog_struct.block_num = 0;

        usbd_enum_error (pudev, req);
        break;
    }
}

/*!
    \brief      handle the DFU_GETSTATUS request
    \param[in]  pudev: pointer to usb device instance
    \param[out] none
    \retval     none
*/
static void  dfu_getstatus (void *pudev, usb_device_req_struct *req)
{
    switch (dfu_status.bState) {
    case STATE_dfuDNLOAD_SYNC:
        if (0 != prog_struct.data_len) {
            dfu_status.bState = STATE_dfuDNBUSY;
            if (0 == prog_struct.block_num) {
                if (ERASE == prog_struct.buf[0]) {
                    SET_POLLING_TIMEOUT(FLASH_ERASE_TIMEOUT);
                } else {
                    SET_POLLING_TIMEOUT(FLASH_WRITE_TIMEOUT);
                }
            }
        } else {
            dfu_status.bState = STATE_dfuDNLOAD_IDLE;
        }
        break;
    case STATE_dfuMANIFEST_SYNC:
        if (MANIFEST_IN_PROGRESS == manifest_state) {
            dfu_status.bState = STATE_dfuMANIFEST;
            dfu_status.bwPollTimeout0 = 1;
        } else if ((MANIFEST_COMPLETE == manifest_state) && \
            (configuration_descriptor.DFU_Function_Desc.bmAttributes & 0x04)){
            dfu_status.bState = STATE_dfuIDLE;
            dfu_status.bwPollTimeout0 = 0;
        }
        break;
    default:
        break;
    }

    /* send the status data of DFU interface to host over EP0 */
    usbd_ep_tx (pudev, EP0_IN, (uint8_t *)(&(dfu_status)), 6);
}

/*!
    \brief      handle the DFU_CLRSTATUS request
    \param      pudev: pointer to usb device instance
    \param[out] none
    \retval     none
*/
static void  dfu_clrstatus (void *pudev, usb_device_req_struct *req)
{
    if (STATE_dfuERROR == dfu_status.bState) {
        dfu_status.bStatus = STATUS_OK;
        dfu_status.bState = STATE_dfuIDLE;
    } else {
        /* state Error */
        dfu_status.bStatus = STATUS_errUNKNOWN;
        dfu_status.bState = STATE_dfuERROR;
    }

    dfu_status.iString = 0; /* iString: index = 0 */
}

/*!
    \brief      handle the DFU_GETSTATE request
    \param[in]  pudev: pointer to usb device instance
    \param[out] none
    \retval     none
*/
static void  dfu_getstate (void *pudev, usb_device_req_struct *req)
{
    /* send the current state of the DFU interface to host */
    usbd_ep_tx (pudev, EP0_IN, &dfu_status.bState, 1);
}

/*!
    \brief      handle the DFU_ABORT request
    \param[in]  pudev: pointer to usb device instance
    \param[out] none
    \retval     none
*/
static void  dfu_abort (void *pudev, usb_device_req_struct *req)
{
    switch (dfu_status.bState){
    case STATE_dfuIDLE:
    case STATE_dfuDNLOAD_SYNC:
    case STATE_dfuDNLOAD_IDLE:
    case STATE_dfuMANIFEST_SYNC:
    case STATE_dfuUPLOAD_IDLE:
        dfu_status.bStatus = STATUS_OK;
        dfu_status.bState = STATE_dfuIDLE;
        dfu_status.iString = 0; /* iString: index = 0 */

        prog_struct.block_num = 0;
        prog_struct.data_len = 0;
        break;

    default:
        break;
    }
}

/*!
    \brief      leave DFU mode and reset device to jump to user loaded code
    \param[in]  pudev: pointer to usb device instance
    \param[out] none
    \retval     none
*/
void  dfu_mode_leave (void *pudev)
{
    manifest_state = MANIFEST_COMPLETE;

    if (configuration_descriptor.DFU_Function_Desc.bmAttributes & 0x04) {
        dfu_status.bState = STATE_dfuMANIFEST_SYNC;
    } else {
        dfu_status.bState = STATE_dfuMANIFEST_WAIT_RESET;

        /* lock the internal flash */
        fmc_lock();

        /* generate system reset to allow jumping to the user code */
        NVIC_SystemReset();
    }
}
